According to enhancing of industries, technology on a membrane with a separating function of high purity is recognized as one of a very important field. Its importance increases in diverse fields including the chemical industry, the food industry, the medicine industry, and medical, biochemical and environmental fields. Especially in the environmental field, as a request for clean water and awareness on water shortage increase, technology using a membrane attracts attention as one of methods for solving the problems.
Meanwhile, a carbon nanostructure is recently discovered and is divided into a carbon nanotube, a carbon nano horn, a carbon graphene and a carbon nanofiber according to its type. In particular, the carbon nanotube is applicable to diverse fields including energy, environment and electronic materials due to superior mechanical strength, heat conductivity and electricity conductivity and chemical stability.
A carbon nanostructure-metal composite is acquired by chemical bonding by inducing a functional group to a carbon nanotube and reacting the induced functional group with metals such as cobalt, copper, nickel, and silver. The carbon nanostructure-metal composite has a superior characteristic in manufacturing structure moldings such as a field emission display, a hydrogen storage binder, an electrode, super capacitor, an electromagnetic waves shield, and light and high strength applications due to a contained metal component.
Methods for manufacturing materials of the carbon nanostructure-metal composite are disclosed in KR Patent Registration No. 0558966 and KR Patent Application Nos. 2007-0072669 and 2008-0049464.
Membranes such as micro filtration (MF) membranes, ultra filtration (UF) membranes, nano filtration (NF) membranes, reverse osmosis (RO) membranes, and ion exchange membranes are used especially in the water treatment field and also used for industrial drainage treatment, water filtering treatment, sewage treatment, waste water treatment, and sea water desalination. A micro filtration membrane is used for a water treatment plant and also used for the sewage treatment by a membrane bio reactor (MBR). The ultra filtration membrane capable of removing bacteria is used for the filtered water treatment and the reverse osmosis membrane is used for a sea water desalination facility. An ion exchange membrane is mainly used for a desalting process. Shizuoka Technology Center developed a nano filtration membrane and was successful in separating green tea components. Yamamoto Group of University of Tokyo developed MBR for advanced water treatment and technology on advanced waste water treatment is planned to be practically applied.
However, membrane fouling is the biggest problem in the membrane. In particular, membrane fouling by microorganism causes deterioration of separating performance to become an obstacle in a membrane lifetime. That is, the membrane fouling by microorganism has a problem of deteriorating the performance of the membrane and reducing its lifetime. Accordingly, researches on a membrane having diverse functions have been continuously progressed to solve the problems.